Web supply mechanism



March 28, @4% w. c. WIEKING 293449952 WEB SUPPLY MECHANISM Filed March 12, 1941' 2 sheets-sheet 1 INVENTOR Ml'm @Y Melt/mg.

AT ORNEY Mard 2, l@ w. c. WIEKIN@ WEB SUPPLY MECHANISM Filed March 12,. 1941 2 Sheets-Sheet 2 INVENTOR William i Wiefu'ng.

ATTORNEY Patented Mar. 28, 1944 UNITED STATES PATENT oFFicE 2,344,952 with SUPPLY MECHANISM William C. wicking, Woodhaven, N. Y., assigner to R. Hoe & Co., Inc., New York, N. Y., a cotporation oi New York Application March 12, 1941, Serial No 382,859

17 Claims.

This invention relates to web supply mechanisms for machines, such as printing machines, adapted for printing newspapers, magazines, etc., and more particularly to improvements in such mechanisms whereby the web tension may be more emciently controlled.

This invention contemplates as its principal object .improvements in a web supply mechanism of the form shown in Patent Number 2,155,431, issued April 25, 1939.

Another object is to provide means to continuously move a member carrying a running belt or other` web tension controlling device, toward an unwinding web roll at proper speed to compensate for tension variations that would rewith a schematic showing of a side view of the web supply mechanism in,normal running position:

The web supply mechanism selected to illustrate the features and principles of this invention is the same as the web supply mechanism sult from the decrease in diameter of the roll as the web is drawn therefrom.

Still another object is to provide in means of the above defined nature, a variable speed device, and means whereby the speed thereof may be automatically changed as a web tension controlling member is being moved toward the web roll.

A further object is to provide electrically operated controls whereby the operation of the continuous drive for the member carrying the web tensioning belt or belts is interlocked with other devices adapted to operate upon the web, whereby a maximum of safety and etliciency in the operation of the entire mechanism will be assured.

It is also an object of this invention to provide a web supply mechanism of generally improved construction, whereby the same will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and efficient in its use.

With the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed.

The preferred embodiment of the invention is illustrated in the accompanying drawings, where- 1n:

Figure l is a side view of a web supply mechanism for a printing machine and embodying the features and principles of this invention;

Figure 2 is an enlarged side view of the drive means for controlling operation of the member carrying the tension controlling device; and

Figure 3 is a diagram of the electrical connections for the various devices of the mechanism and including the controls therefor, together shown and described in the specification of Patent Number 2,155,431, issued April 25, 1939, but with the improvements of this invention incorporated in its structure. As fully shown and described in the patent specication mentioned, the web supply mechanism includes the usual machine frame members il, l2 and i3, and brackets lll secured upon the spaced apart vertical frame members l2 and in which the opposite ends oi the shaft l5 of a web roll supporting reel i6 are journaled. The reel iii is adapted, in this instance, to support a running and expiring web roll il, and a replacement web roll i8, both of which are shown in web renewing position, the web roll i8 being in position for normal running after the web thereof has been connected to the web i9 shown running from the expiring web roll il.

As in the aforesaid patent, a web vjoining device is provided to join the webs of the rolls il and i8, and this device comprises arms 2l and 22 which are commonly pivoted at 23 to a bracket 22, extending downwardly from the upper horizontal frame member i3. The arms 2l and 22 are adapted to be swung from an inoperative position (see Figure 3) to the operative position shown in Figure 1. Arms 2i carry a web deecting brush 25 and arms 22 carry supplemental arms 2S supporting a web severing blade 2l. After the arms 2i and 22 have been swung into the operative position shown in Figure l, they may be manipulated by a hand lever 28, acting through a cable 29 and under the control of suitable electrical devices, to iirst press the running web i9 against the web roll i8 to join the webs together, and then to project the web severing knife 2l and sever the web running from the expiring roll il, the web roll I8 then becoming the running roll from which the web i9 is fed to the machine.

The running web roll, be it Il or i8, due to being mounted upon the reel i6, may be adjusted to align the web sidewise by adjustment of the reel i6 axially, by an electric lmotor 3| acting through gearing in a gear casing 32, and the reel I6 may be rotated to position the web rolls by means of an electric motor 33 acting through gearing in a gear casing 34. 'Ihe motors 3| and 33 are controlled by suitableelectrical controls as hereinafter explained.

Means are provided by this web supply mechanism, to eilect a uniform tension on the web I8 running into the printing machine, and they include, a swingable arm 35 having a roller 36, which is disposed in a loop in the web i9 between web guiding rollers 31 and 38, the web I9 leading from the running web roll I1 or I8 over rollers 33 and 4| to the roller 31, and from the roller 38, over a roller 42 to the printing machine. A web roll rotating and braking means forms a part of the web tensioning mechanism, and includes one or more web roll contacting belts 43, which are led around pulleys 50 carried on arms 40, which are pivotally supported on swingable arms 44. An electric motor 45 is provided to swing the arms 44 and thereby move the belts toward or away from the web roll and coiled springs 48 are arranged to bias the arms 40 so as to keep the belts under tension. 'I'he motor 45 is of the type wherein a speed reducing means is directly associated therewith, and has an electrically operated brake 41.

'I'he motor 45 is drivingly connected to the belt arms 44 through a bevel gear 48 and a gear segment 49, to swing the belt arms to increase or decrease the wrap of the belts 43 about the web roll, and thereby increase or decrease the tension on the web I8 being fed to the machine. Suitable controls are provided for eiilciently controlling the operation of the motor 45. The belts 43 carried by the arms 44 are driven slightly slower than the speed of the running web. by a machine driven shaft 5I, which is connected by means of bevel gears 53 and 54 to a shaft carrying a pulley 52, over which the belts 43 are led.

The controls for the motor 45 include a pair of electrical switches 55 and 56 disposed in a casing 51 and adapted to be actuated b v switch operating members 53 and 59. The members 58 and 53 are adiustably mounted on a reciprocable rod 8l connected by a link 82 to a lever arm 63. 'I'he arm 53 is secured to. and swingable with the lever arm 35. The arm 35, and with it, the arm 83. is swung when variations in the tension of the web I! cause the loop supporting the roller 36 to lengthen or shorten the tension oi' a coil spring 54 being set to maintain the desired operating tension by an adjusting nut 65. Variations in web tension are thereby corrected as the motor 45 will be actuated in the proper direct-ion to either raise or lower the arms 44 and decrease or increase the wrap of the belts 43 about the web roll.

As the web roll decreases in diameter, the wrap of the belts 43 thereon decreases, causing a decrease in web tension. and the arm 35 will swing to move the rod 6|. When the rod 6I has moved a determined amount, the "more tension switch 58 will be energized, and the motor 45 will immediately operate to lower the belt carrying arms 44 to cause increased wrap of the belts 43 about the web roll. Means is provided to prevent a hunting action being set up whenever either of the switches are being operated, and is shown diagrammatically in Figure 3. A motor driven cam controlled switch 65 is provided for this purpose, and is connected into the electrical circuit oi the switches 55 and 56, whereby the energization of the motor 45 will be by timed impulses, rather than continuously. To prevent the arms 44 from being moved either upward and downward beyond the safe amount, an up limit switch 61, and a "down" limit switch 88 are provided to stop the operation of the motor 45.

In accordance with the teachings of the aforementioned Patent 2,155,431, provision also is included to prevent the operation of the reel rotating motor 33 and the web tensioning motor 45 when the arms 2| and 22 are in operative position as shown in Figure 1, and during their operation to join the webs. The means for so doing includes switches 69 and 1I which are operable by movements of the arms 22 and hand lever 28, into operable position, and are arranged to be in control of the reel rotation and web tension motor circuits respectively. Other instrumentalities, such as the provision of manually operable means, herein shown as a handle 12, for adjusting the switch operating members 58 and 59, and means to time the web joining operation are the same as those shown in the hereinbefore mentioned specification.

In combination with the above features and elements, this invention includes the provision of press driven means to slowly rotate the bevel gear 48 to gradually swing the arms 44 downwardly and increase the wrap of the belts 43 on the web roll engaged thereby, in order to compensate for the decrease in the diameter of the web roll, as the web is being drawn therefrom.

While the motor operated means for controlling the motion of the arms 44 in response to movement of the roller 36, controls the tension on the web in a very satisfactory manner, the mechanism herein disclosed is a further advance in the art. The arms 44 are operated under normal conditions by a driving connection with the press which moves the arms downward very slowly but constantly while the press is running, and at a variable speed which increases as the web roll speed increases, due to its decreasing diameter. In normal operation, there is only a gradual motion of the arms, and this maintains an unvarying tension on the web, thereby avoiding even the minute variations that may be caused by an intermittent motion of the arms 44 when they are moved only by the motor 45 in response to the variation in tension that is reflected in a change in the position of the roller 36.

The means shown herein for continuously moving the arms 44 downwardly to increase the wrap of the belts 43 upon the web roll, includes an extension 13 on the shaft of the motor 45 having a. member 14 of a magnetic clutch with its electrical contact rings 15 and 'i6 mounted and secured thereon. The other member 11 of the magnetic clutch is secured upon the end of a shaft 18 in operating alignment with the member 14.

The shaft 18 is extended through suitable bearings 19 and 8i, and has a pair of adjustable and opposing sheave members 82 and 83 thereon. A belt 84 running between the opposing sheave members 82 and 83, cooperates with a pair of adjustable and opposing sheave members 85 and 86 on a shaft 81 shown mounted in bearings 88 and 89. The respective pairs of sheave members 82--83 and 85-86 are slidable axially upon the respective shafts 18 and 81 in the usual manner to vary their relative speeds, whereby they form a variable speed unit of the so-called Reeves" type.

Simultaneous shifting of the pairs of sheaves 82-83 and 85-88 is effected by a system of levers 9|, 92, 94 and 95, pivotally connected to collars on the shafts 18 and 81. The shaft 81 has a cone pulley 98 thereon, and is driven by a belt. 99 from a corresponding cone pulley |00 secured to a shaft |I that is driven by a suitable connection not shown) with any convenientl rotating member of the machine. i

The levers 92 and 94 are suitably fastened together for moving as a unit about a pivot 96. Similarly, levers 9| and 95 are fastened together to move as a unit about a pivot 91, and the levers 9 I and 92 are connected by a slotted connection and pivot S3. It will be seen that downward movement of the lever 92 will move the sheave members 82-83 to separate them and decrease their effective diameter where engaged by the belt 84, and simultaneously the sheave members 85-85 will be moved toward each other and increase their effective diameter where engaged by the belt, this action resulting in increasing the speed of the shaft 18.

The means for automatically eiiecting the desired variation in the speed of the shaft 'i8 and through it the desired lowering speed of the arms 44, includes a cam |02 arranged to be rocked as the arms 45 are swung. The cam |02 is preferably sedured to a shaft to which the arms d4 are secured, and has a roller |03 riding upon its periphery. The roller |03 is carried by a reciprocable rod |04 that is acted upon by a spring |05, reacting against a bearing block |06 for the rod |04, to constantly urge the roller |03 against the cam |02.

The arrangement of the parts of the automatically controlling means is such, that, as the arms B4 are lowered, the cam |02 acts on the roller |03 to raise it and the rod |04. This rod is pi'votally connected to one end of a lever I 0l pivoted at |98, the other end of the lever |01 being connected to one end of a link |09 that is preferably adjustable in length. The other end of the link |09 is connected to the outer end of the lever 92, and hence will move the lever 92 and adjust the variable speed unit by axially shifting the sheavc members 82-83 and 85-86 when the arms M are moved. By manipulation of a threaded rod i|| secured to a lug ||2 in one part of the link |09, and which is screw-threaded through a lug ||3, secured to the other part of the link |09, a variation in the speed of the shaft 'i8 may be effected independently of the variation caused by the variable speed unit.

Variation in the thickness of paper will vary the number of revolutions a roll will make while being unwound, and consequently with a given machine speed, a roll of paper having twice the thickness of the paper of another roll, will become exhausted in one half the time. Cone pulleys 98 and 99 provide means for adapting the mechanism herein disclosed, to papers of various thickness dimensions. Obviously, this compensation can be effected by other means, such as change gears, or if still closer regulation is desired, a variable speed mechanism of the type hereinbefore described may be employed as a driving means between the shafts |0I and 8l.

Under normal running conditions, the arms M will be swung at such a rate that the motor 45 will not be required to operate; but if for any reason, the tension on the web I9 should vary to such an extent that the motion of the roller 36 is suicient to close either oi the switches 55 or 56, the arms 64 will be swung by the motor 45 to increase or decrease tension as may be required to restore it to normal, after which the arms 44 will again vbe moved by the shaft |0I.

Referring now to Figure 8, which shows the gether with dotted line indications of the principal parts of the web supply mechanism, a coil I I5 is arranged to actuate switches I I4 and I I6. This coil is preferably connected directly in parallel with the coil of a main motor control switch (not shown). Il desired, however, the switches |I4 and ||6 may be operated by a direct mechanical connection with the main motor switch, such provision being made that the switches are closed when the motor switch is closed, and opened when the motor switch is opened. The switch ||6 is connected by a conductor Yto the magnetic clutch contact ring l5. A switch I|8 actuated by a similar control coil II 9 correspondingly arranged with respect to a switch (not shown) for the usual threading motor of the printing machine, is normally open, but if closed, would be connected to the contact ring 'l5 'by the conductor II'I. The other Contact ring '76 is connected to the line wire L2. A conductor |2| leads from the switches I I6 and H8 to and through normally closed switches I 22 and |23 actuated by the less tension and more tension control coils |24 and |25 respectively for the tension motor 45. From the switch |23, the circuit continues through a conductor |26 to a normally closed switch |27 actuated by a coil |28. From the switch |27, the circuit leads through a conductor |29 to a normally closed switch |3| in association with the up limit switch 6l, and with it, is adapted to be opened by the movement of the arms 66 into their extreme up position.

From the switch I 3| and by a conductor I 32. the circuit continues to a normally closed switch |33 in association with the down limit switch 68, which with it, is opened by the movement of the arms d into their extreme down position in relation to the running web roll, such position being governed by the engagement'of a switchl operating lever I 39 with the now running web roll I8. The circuit continues from the switch |33, through a conductor |35 to and through normally closed switches I 36 and |37 actuated :by the forward and reverse control coils |38 and |39 respectively for the reel rotating motor 33. The switch |31 is now connected to the line wirc L|.

It will be noted that when the machine is not running, the coils H5 and |I9 are deenergizcd, the switches ||6 and ||8 are opened, and the clutch ld- 11 will be released, even though all the other switches in the clutch energizing circuit are closed, but when either the main motor and control coil ||5 or the threading motor and control coil ||9 are energized, one or the other of switches II6 or ||8 will be closed. The switches |22 and |23 however, are arranged to open and deenergize the clutch H-TL when either of the control coils |24 or |25 for the tension motor 45 are energized, and the switches |36 and |37 in the same circuit, are arranged to open when either of the control coils |38 or |39 fer the reel rotating motor are energized. I'he switches |3I and |33, also in the same circuit, are arranged to open whenever either of the associated arm movement limit switches 6l or 68 respectively are opened by movelnent of the arms M into their aforesaid extreme positions. The

. switch |21 is arranged to open to deenergize the electric control devices and their circuits toclutch 'I4-'Il when the coil |28 is energized. The coil |28 is energized when the web joining arms 2| and 22 are down in operating position as shown in Figure 1, the control switch 69 for this coil then being closed.

While the principal features of this invention have been described above in relation to the various parts and devices fully shown and described in the aforesaid Patent 2,155,431, other control circuits are shown in Figure 3, which are not directly affected by the controls required for this invention. These additionally shown controls are fully described in the aforesaid patent and comprise generally control coils 4| and 42 for the web margin motor 3| and which are commonly connected to the line wire LI, and respectively connected to reel axial movement limit switches |43 and |44, which in turn are in series respectively with push button switches |45 and |46, whereby the motor 3| may be manually actuated to align the web margins.

In addition to the' before-mentioned control coils |38 and |39 for the reel rotating motor 33, there is also provided means to energize these coils |38 and |39 including push button forward and reverse switches |41 and |48 respectively. The down contacts of the forward movement switch |41 are connected to the line wire L2, and through a coil controlled switch |49 to ,the forward control coil |38. From the coil |38, the circuit continues to the switch 1I actuated by the handle 28, and then through an emergency stop switch |5I, controlled by a coil |52 ,to the line wire LI. The reverse movement switch |48 connects the coil |39 to the line Wire L2, and 4from the coil |39, the circuit continues through the same path as does the forward control circuit. By passing through the switch 1|, which is normally closed when the hand lever 28 is in inoperative position, the reel motor circuits are under its control and thus when a web join is to be made, the switch 1| is opened to prevent rotation of the reel I6 by the motor 33.

Preparatory to making a web Join, the reel I6 is rotated to position the web roll I8, and the belt arms 44 are raised. These operations are accomplished by closing a push button switch |53 to energize switch closing coils |54 and |55.` The circuit starting at the switch |53, which is connected to the line wire L2, continues to the coil |55, and thence to a switch |56, controlled by a coil |51, to the line Wire LI.` The coil |54 may also be connected to the line wire L2 through the push button switch |53, and is connected to a normally closed reel rotation limit switch |58. From the switch |58, this circuit leads through the switch 1| to the emergency switch I5 I, and thence to line wire LI. The coil |54 closes a circuit sustaining switch I59, the circuit of which may be opened by a normally closed push button switch |6I.

Energization of the coil |55 will close a switch |62, whereby the arms 44 will be raised by the motor 45, and open the switch |49 to prevent operation of the reel rotating motor 33. Closing of the switch |62 will connect the line wire .LI to a switch |63 controlled by the coil |51. From the switch |63, the circuit continues to the tension motor control coil |24, and then to a switch |64 controlled by the coil |28. The switch |64 is connected to the line L2 by suitable connections (not shown), but in the control circuit of the reel rotating motor 33. Energization of the coil |24 actuates the motor 45 to raise the arms 44 to the limit, whereupon the limit switch 61 is opened to deenergize the coil |51. Deenergization of the coil |51 will open the switches |63 and |56, and also a switch |65, whereby the motor 45 will be stopped and the brake 41 set to hold the arms 44 in their up position. When the switch |56 is opened, it deenergizes the coil |55 thereby closing the switch |49 and energizing the coil' |38, which starts the motor 33, and the reel is rotated thereby until the replacement roll reaches web joining position, when the motor is stopped by the limit switch |58. Various other controls, such as coil controlled switches |66, |61, |68 and |69, closed snap switches |1| and |12, push button switches |13 and |14, switches E15, |16 and |11, and a. solenoid |18 are provided and are connected into the various circuits for control, timing and interlocking purposes as fully described in the specification of Patent 2,155,431.

As fully hereinbefore explained, means such as the magnetic clutch 14-11 is provided to connect the machine driven shaft IIII to the shaft extension 13 of the motor 45 to continuously lower the arms 44 as the web I9 is fed from the running web roll I1 or I8 during the operation of the machine. to gradually increase the speed of the shaft 18 as the diameter of the web roll decreases. The means for so connecting the shaft 13 to the machine drive will be disconnected however, whenever the printing machine is stopped, the web `tension motor 45 is energized, the web joining mechanism is in operative position, the belt arms 44 are at either their "up or down limit position, or the reel rotating motor 33 is energized.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, and it will be further understood that eac'n and every novel feature and combination present in or possessed by the mechanism herein disclosed forms a part of the invention included in this application.

What I claim is:

l. In a web supply mechanism, means to rotatably support a web roll from which a web is drawn and led into a printing machine, means to apply a braking action on the periphery of the web roll as it is rotated by the pull of the web, means driven in timed relation with the machine and acting normally to continuously feed the braking means toward the axis of the web roll as the roll decreases in diameter due to the web being withdrawn therefrom; and means controlled by web tension to move the braking means toward and away from the axis of the web roll.

2. In a web supply mechanism, means to rotatably support a web roll from which a web is led into a printing machine, means to apply a braking action on the periphery of the web 4roll as it rotates, means driven in timed relation with the machine and acting` normally to continuously move the braking means toward the axis of the web roll as the roll decreases in diameter due to the web being withdrawn therefrom, and means to gradually increase the speed of movement of the braking means toward the web roll as its diameter decreases.

3. In a web supply mechanism, a rotatable support for a web roll from which a web is drawn and led into a printing machine, means to rotate the support to position the web roll, means movable to apply a braking action on the periphery of the web roll as it is rotated by the pull of the web, means driven in timed relation with the machine and acting normally to continuously move the braking means toward the web roll as the roll decreases in diameter due to the web being with- Means has also been provided.

drawn therefrom, means controlled by web tension to move the braking means toward and away from the axis of the web roll, and means to interrupt the movement of the braking means when the support rotating means is actuated.

4. In a web supply mechanism, means to rotatably support a web roll from which a web is led into a printing machine, means to apply a braking action on the periphery ofthe web roll as it rotates, means acting intermittently to adjust the braking means automatically when the ten-- sion on the web varies, means normally acting continuously to adjust the braking means as the roll decreases in diameter due to the web being withdrawn therefrom, and means to interrupt the action of the continuously acting adjusting means when the intermittently acting adjusting means is actuated.

5. In a web supply mechanism, a support for a web roll from which a web is withdrawn, a, swingable arm, a running belt supported by the arm and adapted to be moved thereby into contact with the periphery of the web roll, a motor for swinging the arm, controls for the motor adapted to be actuated by variations in tension of the web being drawn from the web roll, to increase and decrease the effective contact of the belt on the roll, and means other than the motor to normally continuously swing the arm to maintain the beit in contact with the roll as the roll decreases in diameter due to the web being withdrawn therefrom.

6. In a web supply mechanism, a support for a web roll from which a web is withdrawn, a swingable arm, a running belt supported by said arm and adapted to be moved thereby into contact with the periphery of the web roll, a motor for swinging the arm, controls for the motor adapted to be actuated by variations in tension of the web being drawn from the web roll to increase and decrease the effective contact of the belt on the roll, means other than the motor to normally continuously swing the arm to maintain the belt in contact with the roll as the roll decreases in diameter due to the web being withdrawn, and means to gradually increase the speed of the continuously swinging means, as the diameter of the web roll'decreases.

7. In a web supply mechanism, a support for a web roll from which a web is withdrawn, a swing'- able arm, a running belt supported by the arm and adapted to be moved thereby into contact with the periphery of the web roll, a motor for swinging the arm, controls for the motor adapted to be actuated by variations in tension oi' the web being drawn from the webroll to increase and decrease the veffective contact of the belt on the roll, meansto continuously swing the arm to maintain the belt in contact with the roll as the roll decreases in diameter due to the web being withdrawn, and means to interrupt the action of the continuously swinging means, when the said motor is actuated.

`8. In a web supply mechanism, a' support for a i web roll from which a web is withdrawn, a swingtinuously swing the arm to normally maintain the belt in contact with the roll as the roll decreases in diameter due to the web being withdrawn. and means actuated with the swinging of the arm to gradually increase the speed of the continuously swinging movement as the diameter of the web roll decreases.

9. 1n a web supply mechanism, means to rotatably support a web roll from which a web is led into a printing machine, a braking device acting ontne periphery of the roll as it rotates, means driven in timed relation with the machine and acting normally to continuously move the braking device toward the periphery of the roll as the roil decreases in diameter due to the webbeii'ig withdrawn, and means acting with movement of the braking device to gradually increase the speed of movement of the braking device toward the periphery of said web roll as its diameter decreases.

10. In a web supply mechanism for a machine operating on a web, a rotatable web roll support, a running belt adapted to engage a web roll on the support, a nrst means acting in response to Variation in web tension to move the belt toward and away from the web roll to increase and decrease the wrap thereof upon the web roll and thereby control the tension of a. web being drawn therefrom, a second means driven in timed relation with the machine to continuously move the belt toward the web roll to compensate for the decrease in diameter thereof as the web is witndrawn, and means to gradually increase the speed oi' the belt movement toward the axis of the web roll by the second means as the roll diameter decreases.

1l. In a web supply mechanism, means to rotatably support a web roll from which a web is led into a printing machine, a braking device acting on the periphery of the roll as it rotates, means to apply the braking device, including means to continuousiy move the braking device toward the periphery of the web roll as the roll decreases iii diameter due to the web being withdrawn, means to control trie device moving means to gradually increase the speed at which the device is moved toward the periphery of said web roll as its diameter decreases, and other means to vary speed or' movement of' the device to compensate foivariation in tne'thickness of webs of diii'erent web rolls.

12. In a web supply mechanism, a rotatable web roll support, a running belt adapted to engage a web roll on the support, a first means to move the beit toward and away from the web iroll to increase and decrease tliejwrap thereof upon the roll to vary the tension of a web being withdrawn, a second means to normally continuously move the belt toward the 4web roll to compensate forA the decrease in diameter thereof as the web is withdrawn, means to gradually increase the speed of the belt movement toward the web roll by said second means as the roll diameter decreases, and means to increase the speed of the increasing means to compensate for a variation in the thickness of webs of different web rolls.

13. In a web supply mechanism, means t0 rotatably support a web roll from which a web is fed into a printing machine, means to apply a braking action on the periphery of the web roll as it rotates, a first means controlled by the tension of the web as it is fed into the machine to quickly adjust the pressure of the braking means, a second means normallyl acting to continuously move the braking means toward the axis of the roll at a continuously increasing speed as the diameter of the roll decreases due to the web being withdrawn therefrom, and means to prevent simultaneous action of both the iii-strand second means. y

14. In a web supply mechanism, means torrotatably support a web roll from which a web is fed into a printing machine, means to apply a braking action on the periphery of the web roll as it rotates, a first means controlled by the tension of the web as it is fed into the machine to adjust the pressure of the braking means, and a second means acting normally to continuously vary the action of the braking means as the diameter of the web roll decreases due to the web being withdrawn therefrom, and means to interrupt the actuation of the second means when the first means is actuated. x

15. In a web supply mechanism having means to support a web roll from which a web is drawn into a printing or like machine, a brake means, means driven in timed relation with the machine andacting to move the brake means to maintain it in determined close contact with the periphery of the web roll as it rotates and a web isbeing drawn therefrom, and a variable speed driving device to progressively increase the speed of movement of the brake means toward the axis of the roll, to compensate for the more rapid change in diameter of the roll as the web is removed therefrom during operation machine.

of the' 16. In a web supply mechanism for a printing machine, a support for a web roll, a brake member adapted to engage the periphery of the roll, a brake applying means, rst actuating means to actuate the brake applying means to slowly move the brake member relatively toward the axis of the roll at a continuous speed governed by the speed of the machine and to increase the speed of movement of the brake member in response to decrease in diameter of the roll, second actuating means acting in response to variation in web tension to actuate the brake applying means to quickly'move the brake member relative to the axis of the roll, and means to prevent simultaneous action of both actuating means.

17. In a web supply mechanism for a printing machine, a support for a web roll, a brake member adapted to engage the periphery of the roll, a brake applying means, ilrst actuating means to actuate the brake applying means to slowly move the brake member relatively toward the axis of the roll at a continuous speed governed by the speed of the machine, a variable speed driving device associated `with the brake applying means to increase the speed of movement of the brake member in response to decrease in diameter of the roll, and second actuating means acting in response to variation in web tensionto actuate the brake applying means t0 quickly move the brake member relative to the axis of the roll.

WILLIAM C. WIEKING. 

